Automatic latching mechanism



arch 28, 1967 J. M. NARDozzA 3,311,394

AUTOMATIC LATCHING MECHANISM Filed Dec. 11, 1964 John Navdozzu,

INVENTORZ United States. Patent Ofiice 3,311,394 AUTOMATIC LATCHING MECHANISM John M. Nardozza, Lawrence, Mass., assignor by mesne assignments, to the United States of America as represented by the Secretary of the Army Filed Dec. 11, 1964, Ser. No. 417,847 6 Claims. (Cl. 292-33) This invention relates to a latching mechanism for positively latching a sliding door in an open position.

In organizational maintenance equipment cabinets, the need has arisen for a latching mechanism that will positively hold a door in an open position in order to assure the safety of laymen who must work. beneath the open door. Also, the latching mechanism must be so fabricated as to prevent accidental contact or jarring of the door from causing the door to close down upon the laymen working there beneath.

Therefore, it is an object of this invention to provide a latching mechanism that automatically latches when the door is opened.

Another object of this invention is to provide a latching mechanism that automatically resets itself upon closing of the door.

A further object of this invention is to provide a latching mechanism that must be first manually tripped and then have the door raised an additional amount before the door can be lowered to the closed position.

A still further object of this invention is to provide a latching mechanism that has a pair of coacting bolts and pawls for latching a door in an open position.

Still another object of this invention is to provide a latching mechanism that is particularly suited for use with extension slides.

In accordance with this invention, an automatic latching mechanism is provided that has a pair of striker mechanisms mounted on one of a plurality of door slides and a bolt latching mechanism that is mounted on another of the door slides. The bolt latching mechanism includes a pair of spring biased bolt members that are maintained in an outwardly extended position by a plunger member that is spring biased to a retracted release position away from the bolt members. A pivotably mounted trigger member is disposed to move the plunger member to an extended position, and a pivotably mounted release lever is adapted to maintain the trigger and plunger in a plunger extended position wherein said bolts are held in the extended position by the plunger member. Each of the striker mechanisms includes a spring biased pawl member that coacts with a notch in one of the bolt members when the bolts are extended to latch a door in an open position. One of the pawl members is in the line of movement of the trigger member so that as the door is moved to the closed position the trigger member is reset to the plunger extended position as the door is closed.

In the accompanying drawing forming a part of this specification, and in which like numerals are employed to designate corresponding parts throughout the same:

The single figure of the drawing illustrates a perspective view, partially cutaway and in section, of an automatic latching mechanism according to this invention.

The invention may be better understood by referring to the drawing wherein, numeral 1 designates a slide track to which striker mechanisms 3 are attached in a conventional manner by bolts 5. Each striker mechanism in cludes a base 7 and a pair of upstanding arms 9. A pawl member 11 is pivotably mounted between arms 9 by pivot shaft 13. Spring 15 biases pawl member 11 outwardly until pin 17 reaches one end of arcuate slot 19 in pawl member 11. The latching end of pawl member 11 has a tapered surface 21 for coaction with bolt latching mechanism 23.

Patented Mar. 28, 1967 Bolt latching mechanism 23 is secured to slide rail 25 in a conventional manner such as by bolts 27 and includes a housing 29 and a cover plate 31 that are secured together in a conventional manner by bolts 3. Housing 29 has oppositely disposed cut outs 35 and 37 for slidably supporting bolts 39 and 41. Bolts 39 and 41 have notches 43 and 45 on one thereof for coaction with pawl members 11 and rounded surfaces 47 and 49 on the other end thereof for coaction with tapered cam surfaces 50 of 'plunger 51. Each bolt has an elongated slot 53 therethrough for receiving a spring 55 therein. One end of spring 55 abuts one end of slot 53 and the other end of spring 55 abuts spring abutment 57 that is integral with housing 29 to spring bias the bolt to an inward and retracted position.

Housing 29 is cut out to slidably mount plunger 51 and has guides 59 for guiding plunger 51 in reciprocal movement. Plunger 51 has an elongated slot 61 therethrough with a spring 63 abutting at one end against one end of slot 61 and at the other end against a spring abutment 65 that is integral with housing 29. Spring 63 biases plunger 51 toward a retracted release position.

A trigger member 65 is pivotably mounted on pin 67 and has an outwardly projecting end 69 adapted for resetting the trigger member 65 and an inwardly project ing portion 71. Portion 71 has notch 73 therein which overlaps with notch 75 of plunger 51 to provide a connection between plunger 51 and trigger member 65. Portion 71 also has a tapered end surface 77 for reception in notch 79 of release lever 81. Release lever 81 is pivotably mounted on pin 83 and has handle end 85 for manual actuation of release lever 81 and an inwardly projecting end 87 that has notch 79 therein. A spring 89 is mounted between the housing and the handle end of release lever 81 to bias release lever 81 into a latching position.

In operation, the door is raised or opened until pawl members 11 become engaged with notches 43 and 45 of bolts 39 and 41 as shown in the figure, To close the door, handle 85 is actuated to release trigger member 65 and allow spring 63 to actuate plunger 51 to a retracted position. At this stage, pawl members 11 are still engaged with notches 43 and 45 of bolts 39 and 41, and the door must be raised slightly to allow pawl members 11 to become disengaged from notches 43 and 45. Bolts 39 and 41 are then snapped inwardly by springs 55. The door is next lowered, and as the door is lowered, outwardly projecting end 69 of trigger member 65 and pawl member 11 contact each other to actuate trigger member 65 to a reset position in which tapered end surface 77 of trigger 65 is reengaged in notch 79, plunger 51 is extended, and bolts 39 and 41 are extended. Just as trigger member 65 is reset, trigger member 65 and pawl 11 pass each other as the door continues to close. This completes the cycle, and the mechanism is now ready to repeat the sequence of operation.

It is to be understood that the form of my invention, herewith shown and described, is to be taken as a preferred example only, and that various changes in the size, shape and arrangement of parts may be resorted to, without departing from the spirit of my invention or the scope of the subjoined claims.

I claim:

1. An automatic latching mechanism including: striker mechanism and bolt latching mechanism mounted for movement relative to each other and including coacting means for latching a door in an open position; said coacting means being so constructed and arranged as to require a two step procedure for releasing such coaction to thereby allow one of said striker mechanism and said bolt latching mechanism to move relative to the other in a door closing direction; and coacting means including at least one pivotably mounted pawl member on said striker mechanism and at least one reciprocally mounted bolt member on said bolt latching mechanism, said pawl member being spring biased toward a latching position and said bolt member being spring biased away from the latching position; and said bolt latching mechanism including a reciprocally mounted plunger for actuating said bolt member to a latching position, a pivotably mounted trigger member interconnected with said plunger for actuating said plunger to a plunger extended position, and a pivotably mounted manual release lever including latching means for latching said trigger member in said plunger extended position.

2. A latching mechanism including: a pair of striker mechanisms adapted to be mounted on opposite sides of a door slide; each of said striker mechanisms including a pawl member pivotably mounted for limited arcuate movement and spring means biasing the pawl member to an extended position; and a bolt latching mechanism adapted to be mounted on another door slide; said bolt latching mechanism including a pair of slidably mounted bolt members that are disposed for projecting outwardly from opposite sides of said bolt latching mechanism into a bolt latching position, each of said bolts being spring biased to a retracted position and including a notch in one end thereof for latching engagement with said pawl members; and actuating and release means for actuating said bolt members to said bolt latching position and allowing said bolt members to be actuated to said retracted position by the spring bias, said actuating and released means including a slidably mounted plunger member having cam surface means for coacting with said bolt members to actuate said bolt members to said bolt latching position, a pivotably mounted trigger member connected to said plunger for actuation thereof, and a manually actuated latching lever means for latching said trigger member in bolt latching position.

3. A latching mechanism as set forth in claim 2, wherein said trigger member has an end projecting from one of said opposite sides of said bolt latching mechanism and in a line of movement toward one of said pawl members to be reset by said one of said pawl members as they pass each other.

4. An automatic latching mechanism including: striker mechanism and bolt latching mechanism mounted for movement relative to each other and including coacting means for latching a door in an open position, said coacting means being as constructed and arranged as to require a two step procedure for releasing such coaction to thereby allow one of said striker mechanism and said bolt latching mechanism to move relative to the other in a door closing direction; said coacting means including at least one pivotably mounted pawl member on said striker mechanism and at least one reciprocally mounted bolt member on said bolt latching mechanism, said bolt member being mounted generally perpendicular to said pawl member, said pawl member being spring biased toward a latching position and said bolt member being spring biased away from the latching position; said bolt latching mechanism including a reciprocally mounted plunger for actuating said bolt member to a latching position and means for holding said plunger in said latching position, said plunger having a cam surface on one end thereof that coacts with a cam surface on one end of said bolt member to hold said bolt member in said latching position.

5. An automatic latching mechanism as set forth in claim 4, wherein said means for holding said plunger includes a pivotably mounted trigger member interconnected with said plunger for actuating said plunger to a plunger extended position, and a pivotably mounted manual release lever including latching means for latching said trigger member in said plunger extended position.

6. An automatic latching mechanism as set forth in claim 5, wherein said trigger member has an end projecting from one side of said bolt latching mechanism and in path of movement toward and away from said pawl member whereby said trigger member is actuated to a reset position as said trigger member and said pawl member pass each other.

References Cited by the Examiner UNITED STATES PATENTS 271,001 l/l 883 Thompson 292 443,804 12/ 1890 Stamm 292-34 1,010,482 12/ 1911 Crowe 292277 2,880,029 3/ 1959 Allen 292-278 MARVIN A. CHAMPION, Primary Examiner.

J. R. MOSES, Assistant Examiner, 

1. AN AUTOMATIC LATCHING MECHANISM INCLUDING: STRIKER MECHANISM AND BOLT LATCHING MECHANISM MOUNTED FOR MOVEMENT RELATIVE TO EACH OTHER AND INCLUDING COACTING MEANS FOR LATCHING A DOOR IN AN OPEN POSITION; SAID COACTING MEANS BEING SO CONSTRUCTED AND ARRANGED AS TO REQUIRE A TWO STEP PROCEDURE FOR RELEASING SUCH COACTION TO THEREBY ALLOW ONE OF SAID STRIKER MECHANISM AND SAID BOLT LATCHING MECHANISM TO MOVE RELATIVE TO THE OTHER IN A DOOR CLOSING DIRECTION; AND COACTING MEANS INCLUDING AT LEAST ONE PIVOTABLY MOUNTED PAWL MEMBER ON SAID STRIKER MECHANISM AND AT LEAST ONE RECIPROCALLY MOUNTED BOLT MEMBER ON SAID BOLT LATCHING MECHANISM, SAID PAWL MEMBER BEING SPRING BIASED TOWARD A LATCHING POSITION AND SAID BOLT MEMBER BEING SPRING BIASED AWAY FROM THE LATCHING POSITION; AND SAID BOLT LATCHING MECHANISM INCLUDING A RECIPROCALLY MOUNTED PLUNGER FOR ACTUATING SAID BOLT MEMBER TO A LATCHING POSITION, A PIVOTABLY MOUNTED TRIGGER MEMBER INTERCONNECTED WITH SAID PLUNGER FOR ACTUATING SAID PLUNGER TO A PLUNGER EXTENDED POSITION, AND A PIVOTABLY MOUNTED MANUAL RELEASE LEVER INCLUDING LATCHING MEANS FOR LATCHING SAID TRIGGER MEMBER IN SAID PLUNGER EXTENDED POSITION. 